rails/rails — pull request #12378 by Aaronneyer (2013-09-26 23:58:55+00:00)
Title: Fix string interpolation vulnerability in Action Mailer

`ActionMailer::LogSubscriber` allows a recipient to contain a format string, which can be combined with a ruby bug to cause a segmentation fault. This switches the string over to use only one form of interpolation.

This is a fix backported from Rails 4.0, as seen here: https://github.com/rails/rails/commit/37852726